When Service Conditions are Equal

Tom has made an excellent map of train verus bus usage in the Northern Suburbs. It's a great, informative resource for everyone involved in this debate, and I encourage you to check it out.

Preferences

His analysis highlights one of the key difficulties, in trying to predict which scenario people will prefer: it's very hard to construct a "fair" comparison between bus and rail. The most common comparison is between trains on tracks and buses on roads - which skews the comparison because the roads are choked up with cars but the tracks are not. The fair comparison would be between trains on tracks and buses on busways. Of course, we can't run both rail and busway to Johnsonville, just to see which people prefer!

If we did, I suspect preferences might be split down the middle, amongst existing rail users. (Trains are more spacious, but buses are more frequent and take you into the CBD.) Existing rail users will be well served, in different ways, by both options. And that's important. The busway must done in such a way that it is a fair deal for existing rail users. If "we" take away their trains, we must compensate with things like more frequent service and seamless travel to the CBD. Things should work out about even (or better) for existing rail users. So this debate is not really about them. This debate is about existing bus users - the people who cannot walk to a rail station, and whose bus routes will suffer increasing delays and congestion if the busway does not go ahead. Already, traffic congestion costs us hours each week, hours which we could be spending with our families. Only the busway will give that time back to us (and our families). Once existing bus users understand that, their preference will be clear.

"When Service Conditions are Equal"

Anyway, back to Tom's comments, about the preferences of commuters who do have a choice. He quotes a page which reads as follows:

Because transit use is a function of travel time, fare, frequency of service, population, and density, increased transit use can not be attributed to rail transit when these other factors are improved. When these service conditions are equal, it is evident that rail transit is likely to attract from 34 percent to 43 percent more riders than will equivalent bus service. The data do not provide explanations for this phenomenon, but other studies and reports suggest that the clearly identifiable rail route; delineated stops that are often protected; more stable, safer, and more comfortable vehicles; freedom from fumes and excessive noise; and more generous vehicle dimensions may all be factors.

Again, that's great stuff, and should considered by everyone involved in this debate.

Are they Equal Now?

Let's look one-by-one at those points. Are service conditions currently equal, between bus and rail?

Travel time: bus has a significant advantage off-peak; rail often has an advantage on-peak (depending on how much traffic congestion is slowing the buses). On-peak rail certainly has an advantage in terms of predictable travel times. I believe Tom's data is journeys to work, so his map relates to on-peak travel choices.

Fare: One month's bus travel from Johnsonville = approx $86 to $103 (depending on how many days in the month, and whether you ride on into the CBD or get off at Wellington station). One month's rail travel = $60 (or $45 on a "Peace Train" ticket).

Frequency of Service: bus is once every 5 mins at height of morning peak; train is every 13 or 26 mins

Population and Density: Tom's approach successfully eliminates these variables (his train and bus passengers come from the same places)

In otherwords, service conditions are not currently equal. I'd be interested to know how the fare differences influence choice.

Factors that Make Rail Attractive

Now, let's look at the likely reasons that attract consumers to rail, according to the page Tom quoted. Fortunately, some of these attractive features can be preserved in the busway scenario.

Clearly Identifiable Rail Route: The busway will follow the same route. (And it will be important to ensure the the "return routes" of the off-peak buses are also clearly identifiable. I see that as a weekness in the current busway scenario, but I think it can be fixed fairly easily. I'll post details when I get round to it.)

Delineated Stops that are Often Protected: The busway will use the same stops (the existing rail stations)

More Stable, Safer, and More Comfortable Vehicles: Rail has the edge here, although it is worth noting that stability and comfort arise as much from the route as from the vehicle. A key ingedient in comfort is a route with gentle grades, gentle curves and no stops and starts caused by traffic congestion. In terms of the route, busway and train are virtually identical (as you would expect if you put a busway on an ex railway track!)

Freedom from Fumes and Excessive Noise: again, an edge for rail, although at least the busway gets away from fumes and noise caused by other vehicles.

More Generous Vehicle Dimensions: rail wins this one too. (Which is ironic, considering how many people are afraid the buses won't fit through the tunnels!)

Conclusion

Comparing rail with bus-on-road is not entirely relevant to this debate. The better comparison is comparing rail with bus-on-busway (serving the same suburbs via the same route) . Unfortunately, that comparison is much harder to make.